Always
Alive
Always alive is a great name for a common plant that most everyone knows - but
not by that English name. You may know it as Houseleek or
Hen-and-chicks. Taxonomists know it as Sempervivum. This
old-fashioned (and common) plant dates back to ancient times. The Romans
grew them in pots. They live up to their Latin name - (semper) always (vivum)
alive - because of their tolerance to drought. These succulent rosettes are
also evergreen.
Sempervivum tectorum, the common house-leek, has been grown for centuries on
house roofs as a protection against lightning and fire, a big worry since
roofs were made of thatch. You can still see them growing on roofs in
Europe and this practice is making a come back. Roof plantings are even
making inroads in the U.S., especially on flat roofs, as a means of keeping
them cooler.
There are over 40 species of semps. They are native to Europe, northern
Africa and western Asia. There are hundreds of different cultivars as
the result of hybridization. As with hostas and other genera that are
easy to hybridize, there sometimes seems to be no distinguishable difference
between different cultivars to the non-aficionado. There are differences
although they can sometimes be very subtle.
There are differences in size. The largest rosettes can be near 9 inches
across while the smallest may be less than 1/4 inch in diameter. There
are also differences in color but the range of colors is not great.
There are light green, grayish green, all shades of green and reddish to
burgundy colored leaves. There are some where the base of the leaf is
green and the tip red and the converse. The color in winter can be
dramatically different from the color in summer, with winter colors being
darker and more reddish.
Semps do bloom; flower colors can vary from whites to pinks through reds. For
the superstitious, it is considered to be bad luck for sempervivum to bloom.
And it is bad luck - for the plant - because semps are monocarpic. That's the
botanical term meaning the rosette dies after it flowers. Obviously, semps are
grown for their foliage and not for their flowers.
There are differences in the shape of the rosettes and the leaves. Some
have open rosettes and in others the leaves curve in. Some have sharply
pointed tips to the leaves and others are more rounded. Some leaves look
glaucous, i.e. powdery, others are hairy and still others are clean-shaven.
My absolute favorite species is S. arachnoideum, the cobweb houseleek.
Very fine hairs grow on the tips of the leaves and stretch from leaf to leaf
so that the top of the rosette looks as if it has a cobweb across it.
Some cultivars are more heavily webbed than others. I think they are all
delightful.
The common name Hen-and-chicks comes from the manner in which most semps
produce offsets, i.e., little clones, that snuggle up to the parent rosette
like a chick to a mother hen in the nest. The chicks are attached to the
hen by stolons, the botanical equivalent of an umbilical cord. The
chicks are produced in spring during the most active growth period. The
stolon can be severed and the chick can be replanted to start a new
family.
Semps in general want full sun.
The rosettes are not as tight in shade. They want well-drained soil, either
sandy or gritty, otherwise they will eventually rot. Most are listed as
being hardy to USDA Zone 5.
Semps are slow growing but will eventually form a mat. In the garden
railroad, mats of the smaller semps give the impression of rocky ground or
weedy terrain. In our railroad, the Puddlefort & Patio, I split the
chicks from mom and plant them in rows to look like cabbages in a market
garden. A friend has planted chicks as a scale hedge around around a
house. Semps will grow on rocks in crevices and can be used to provide
the flora on a stone mountain in the layout.
Mountain Crest Gardens in Etna, California, sells Red Cedar birdhouses with
sempervivum and sedum growing on the roof. If you have a European style
layout, you might consider trying something similar to give the impression of
an old thatched cottage.
Various craft stores sell tiny flower pots, thimble size and larger. The
trouble with using live plants in very small pots is they have to be watered
very frequently or the plants will die. Because sempervivum can tolerate
drought, single rosettes can be planted in these small pots and used as
planters in front of buildings.
Although they will not be lush if you
forget to water them, they will stay alive.
You frequently can find pots of sempervivum in local nurseries but they
usually do not have any species or cultivar names. Check the largest
rosette in the pot to get an idea of the ultimate size. You can get
semps from mail-order catalogs. The problem with catalogs is that there
aren't any pictures. Frequently there is not an adequate description of size.
What I generally do is write a note explaining that I want them for my garden
railroad and would like them to send the smallest varieties they have that
will be hardy for me. If you are willing to wait for your order and if
you don't order during the busiest period for nurseries, i.e., spring planting
time, and you are ordering enough to make it worth their time, most nurseries
will be happy to oblige you in selecting suitable plants.
In general, semps run $2.50 to $3.00, except for the rarest forms.
You will get a mature rosette and 2 or 3 chicks. They will arrive bare
root and will have to be potted up soon after you get them.
Two nurseries that I have ordered plants from are:
Squaw Mountain Gardens
P.O. Box 946
Estacada, Oregon 97023
503-630-5458
www.squawmountaingardens.com
Mountain Crest Gardens
P. O. Box 724
Etna, CA 96027
530-467-3215
877-656-4035
www.mountaincrestgardens.com
I will have a few pots for sale at the meeting at Kimmels'. |